Sonde devices including a sectional ferrite core structure

ABSTRACT

Sonde devices for providing magnetic field signals for use with utility locators or other devices are disclosed. In one embodiment a sonde device includes a housing, a core comprising a plurality of core sections, and one or more support structures, which may include windings. Circuit and/or power supply elements may be disposed fully or partially within the core to control generation of predefined magnetic field frequencies and waveforms.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. $ 119(e) to co-pendingUnited States Provisional Patent Application Ser. No. 61/701,565, filedSep. 14, 2012, entitled SONDE DEVICES INCLUDING A SECTIONAL FERRITE CORESTRUCTURE, and to co-pending United States Provisional PatentApplication Ser. No. 61/789,074, filed Mar. 15, 2013, entitled SONDEDEVICES INCLUDING S SECTIONAL FERRITE CORE STRUCTURE. The content ofeach of these applications is incorporated by reference herein in itsentirety for all purposes.

FIELD

This disclosure relates generally to sonde devices, as well as methodsof making and using such devices. More particularly, but notexclusively, the disclosure is directed to sonde devices for highfrequency use having multiple ferrite arc core section elements andcircuitry to generate output magnetic field signals at one or morefrequencies.

BACKGROUND

In a typical application, a sonde, which is a device for generatingmagnetic fields within a pipe, conduit, or other cavity, is positionedwith the pipe to generate output magnetic fields. An associated magneticfield locator is used above-ground, typically at or near the groundsurface, to locate the position of the sonde relative to the surfaceand/or determine the sonde's depth.

Conventional sonde devices often employ a core structure composed ofmetals such as steel or a cylindrical bar of ferrite. As such, thesecore structures, used with batteries, are not optimized at reducing eddycurrents resulting in a loss of efficiency for the sonde device.Furthermore, conventional sonde devices may be configured to onlyoperate at one frequency, thereby allowing for less than ideal detectionunder certain circumstances where multiple and/or variable frequencymagnetic field signals would be useful.

Accordingly, there is a need in the art to address the above-describedas well as other problems.

SUMMARY

The present disclosure relates generally to methods and systems of sondedevices capable of being inserted into pipes or other conduits andemitting magnetic field output signals at one or more frequencies forlocating purposes. Embodiments of sonde devices as described in thepresent disclosure may be used with a buried object locator deviceenabled to sense the emitted frequency or frequencies from the sondedevice to trace and/or map buried pipe, conduits, other utilities orcavities.

For example, in one aspect the disclosure relates to a sonde device asmay be used in buried object locating systems. The sonde device mayinclude, for example, a housing, which may be a structural and/orwaterproof housing. The housing may include threaded or otherwisesealable caps or openings to load or unload batteries or other internalelements. The sonde device may further include a core. The core mayinclude a magnetic section with a plurality of core section elements.The core may further include one or more support structures forpositioning the core section elements. The core may include one or morewindings. The one or more windings may be disposed about the corestructure. The windings may include primary and secondary windings.

In another aspect, the disclosure relates to a sonde that may include acore structure including two or more ferrite arc core section elementsconfigured to optimize the reduction of eddy currents. In someembodiments, other materials, besides ferrites, may be used to reduceeddy currents.

In another aspect, the disclosure relates to a system for locatingburied objects wherein a sonde device may be used in conjunction with anassociated locator device and may be capable of emitting output magneticfield signals at two or more frequencies. In some embodiments, thefrequencies may be manually switched by a user. In other embodiments, anautomatic frequency switching scheme may be used in conjunction with anenabled locator device. In some embodiments, the frequencies emitted mayinclude 512 Hz and 32,768 Hz.

In another aspect, a color changing light which may be an RGB LED may beadded to a sonde in keeping with the present disclosure. In suchembodiments, the light color may correspond to a particular frequency,thus providing a visual indicator of frequency to a user. The colorscheme may be arranged in a spectrum whereby the correspondingfrequencies may be arranged from low to high or high to low. Somecolors, flashing of lights or rotation of colors may also correspond toother data. For instance, a white light may indicate low battery.

In another aspect, a sonde device in keeping with the present disclosuremay be configured to allow a central passage allowing the sonde deviceto be used with a push jetter, horizontal directional drilling rig,other boring tools, etc. that may require fluids, air, or othermaterials to be pumped to and or removed through such a central passage.In such embodiments, batteries, such as Lithium Polymer batteries, maybe wrapped into curved sections to surround the central passage.

In another aspect, a sonde device in keeping with the present disclosuremay be enabled to transmit data to an enabled locator device or otherdevice. For instance, binary phase shift keying or other encodingschemes may be used to communicate orientation of the sonde from ahorizontal or vertical axis and/or signal strength of the sonde. In someembodiments where the signal strength is known, an enabled locatordevice may be enabled to recognize and compensate for degradation of themagnetic field of the sonde device as its battery discharges. In anotheraspect a sonde device in keeping with the present disclosure may beenabled to regulate constant power to a sonde with a known current. Thesignal output by the sonde may be measured and such measurements may beused to further control the output. Pulse-width modulation or othersimilar technique may be utilized to regulate the power.

In yet another aspect, temperature compensated crystal oscillators(referred to hereafter as TCXO) or voltage controlled temperaturecompensated crystal oscillator (VCTCXO) may be used to provide a preciseand stable time reference on the sonde to allow the phase to be trackedand/or allow synchronous detection techniques to be used

Various additional aspects, features, and functionality are furtherdescribed below in conjunction with the appended Drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present application may be more fully appreciated in connection withthe following detailed description taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 illustrates an embodiment of a sonde device in use in a typicaltracing/locating application.

FIG. 2 is an isometric view of the sonde device embodiment of FIG. 1.

FIG. 3 is a top down exploded isometric view of the sonde deviceembodiment of FIGS. 1-2.

FIG. 4 is a bottom up exploded isometric view of a sonde deviceembodiment of FIGS. 1-3.

FIG. 5A is a sectional view of the sonde device embodiment of FIG. 2,along line 5-5.

FIG. 5B is an illustration of an embodiment of an LC circuit.

FIG. 6 is a top down exploded isometric view of an embodiment of a coreassembly.

FIG. 7 is an isometric view of the core assembly embodiment revealing aPCB.

FIG. 8 illustrates the core assembly embodiment of FIG. 7 with coilwindings and outer core tube removed to reveal the ferrite arc sections.

FIG. 9 illustrates an embodiment of a frequency switching process foruse in a multi-frequency sonde device.

FIGS. 10A & 10B illustrates details of an embodiment of a sonde devicecore including four arc core section elements.

FIG. 11 illustrates details an embodiment of a sonde device core withtwo arc core section elements;

FIG. 12 illustrates details of an embodiment of a sonde device core withthree arc core section elements;

FIG. 13 illustrates details of an embodiment of a sonde device core withfour arc core section elements and an internal structural supportelement for the core section elements.

FIG. 14 illustrates details of an embodiment of a sonde device withpower and circuitry enclosed within a core including four ferrite arccore section elements.

FIG. 15 illustrates details of an embodiment of a sonde device and coilwindings.

FIG. 16A is an illustration of a sonde embodiment allowing a centralpassage.

FIG. 16B is an illustration of an alternative sonde embodiment allowinga central passage.

FIG. 16C is an illustration of one embodiment of a core structureconfiguration.

FIG. 17 is an illustration of an embodiment of curved batteries fromFIG. 16A.

FIG. 18 is an illustration of a sonde embodiment similar to theembodiments of FIGS. 16A or 16B on a on a sewer or push jetter.

FIG. 19 is an illustration of a sonde embodiment similar to theembodiments of FIGS. 16A or 16B on a horizontal directional drillingsystem.

FIG. 20 is an illustration of an embodiment of a sonde in an inductivecharger.

FIG. 21 is an illustration of an alternative embodiment of inductivelyrecharging sonde batteries.

FIG. 22 is an illustration demonstrating an embodiment of data broadcastfrom a sonde.

FIG. 23 is an illustration demonstrating an embodiment of data broadcastfrom a sonde.

DETAILED DESCRIPTION OF EMBODIMENTS Overview

This disclosure relates generally to sonde devices and methods of makingand using such devices. More particularly, but not exclusively, thedisclosure is directed to sonde devices for high frequency use havingmultiple ferrite arc core section elements and circuitry to generatemagnetic fields at one or more frequencies. Embodiments of sonde devicesas described in the present disclosure may be used with a locator deviceenabled to sense the emitted magnetic field output signals, at one ormore frequencies, from the sonde device.

For example, in one aspect the disclosure relates to a core structureincluding two or more arc section elements for reducing eddy currents.The arc section elements may comprise a ferrite material. Othermaterials besides ferrites with eddy current reduction properties mayalso be used in various embodiments. Embodiments for low frequencyoperation may use other materials, such as soft steel.

In another aspect, the disclosure relates to a sonde device configuredto emit output magnetic field signals at one or more frequencies, suchas at the 512 Hz and 32,768 Hz frequencies. The frequencies may beeither manually switched by a user or automatic switched using a timedswitching circuit. In such an embodiment, a system may include a sondeand a locator device configured to detect the frequency switching.

In another aspect, the disclosure relates to a sonde device as may beused in buried object locating systems. The sonde device may include,for example, a housing, which may be a structural and/or waterproofhousing. The housing may include threaded or otherwise sealable caps oropenings to load or unload batteries or other internal elements. Thesonde device may further include a core. The core may include a magneticsection with a plurality of core section elements. The core may furtherinclude one or more support structures for positioning the core sectionelements. The core may include one or more windings. The one or morewindings may be disposed about the core structure. The windings mayinclude primary and secondary windings.

The core section elements may be, for example, arc core section elementshaving at least one arc in the cross-sectional shape. The core sectionelements may comprise ferrite or other ferromagnetic materials or othermagnetic metals such as Mu-metal, Nickel, etc. The core section elementsmay comprise steel, such as a soft magnetic steel. The core sectionelements may have a rectangular cross-sectional shape.

In some embodiments the plurality of core section elements may consistof two core section elements. In other embodiments the plurality of coresection elements may consist of three core section elements. In otherembodiments the plurality of core section elements may comprise four ormore core section elements.

The core may further include, for example, a battery and a circuitelement for providing current to the winding to generate an outputmagnetic field signal. The battery and the circuit element may bedisposed partially or entirely within a volume enclosed by the pluralityof core section elements. The circuit element may include circuitry forgenerating the current to provide the output magnetic field signals attwo or more frequencies. The output signal may be switched between thetwo or more frequencies. One or more signal or power wires may bedisposed in an axial gap between ones of the plurality of core sectionelements.

In some embodiments, the sonde may be configured to transmit data to anenabled locator device. For instance, data regarding the sonde'sorientation from a horizontal or vertical axis and/or signal strength ofthe sonde.

Various additional aspects, features, and functions are described belowin conjunction with FIGS. 1 through 23 of the appended Drawings.

It is noted that as used herein, the term, “exemplary” means “serving asan example, instance, or illustration.” Any aspect, detail, function,implementation, and/or embodiment described herein as “exemplary” is notnecessarily to be construed as preferred or advantageous over otheraspects and/or embodiments.

The following exemplary embodiments are provided for the purpose ofillustrating examples of various aspects, details, and functions of thepresent disclosure; however, the described embodiments are not intendedto be in any way limiting. It will be apparent to one of ordinary skillin the art that various aspects may be implemented in other embodimentswithin the spirit and scope of the present disclosure.

Example Sonde Device Embodiments

In a typical buried object locating/tracing operation, a sonde ispositioned within a pipe, conduit, other utility or cavity and energizedto generate magnetic field signals for detection by a buried objectlocator (also denoted herein as a “locator” for brevity) in what iscommonly referred to as a “locate” or “tracing” operation. Turning toFIG. 1, an example tracing operation 100 in illustrated. As shown inFIG. 1, an embodiment of a sonde as described in the present disclosure,such as a sonde device 110 as shown, may be attached to a push-cable 120on a cable reel 130 and inserted into a pipe 140 by a user 150. Whenactivated, a magnetic field signal at least one frequency may be emittedfrom the sonde device 110 such that a user 150 may locate the positionof the sonde device 110 with the use of locator 160.

Some example locators and sondes and associated configurations andfunctions are described in co-assigned patents and patent applicationsthat may be used in conjunction with the sonde and locator systemteachings herein include U.S. Pat. No. 7,009,399, entitledOMNIDIRECTIONAL SONDE AND LINE LOCATOR, issued Mar. 7, 2006, U.S. Pat.No. 7,443,154, entitled MULTI-SENSOR MAPPING OMNIDIRECTIONAL SONDE ANDLINE LOCATOR, issued Oct. 28, 2008, U.S. Pat. No. 7,518,374, entitledRECONFIGURABLE PORTABLE LOCATOR EMPLOYING MULTIPLE SENSOR ARRAY HAVINGFLEXIBLE NESTED ORTHOGONAL ANTENNAS, issued Apr. 14, 2009, U.S. Pat. No.7,619,516, entitled SINGLE AND MULTI-TRACE OMNIDIRECTIONAL SONDE ANDLINE LOCATORS AND TRANSMITTERS USED THEREWITH, issued Nov. 17, 2009, andU.S. Provisional Patent Application Ser. No. 61/485,078, entitledLOCATOR ANTENNA CONFIGURATION, filed on May 11, 2011. Furtherinformation regarding systems, devices, and methods used with andotherwise relating to pipe sonde devices in keeping with the presentdisclosure may be found in U.S. Pat. No. 6,958,767, entitled VIDEO PIPEINSPECTION SYSTEM EMPLOYING NON ROTATING CABLE STORAGE DRUM, issued Oct.25, 2005, U.S. Pat. No. 7,221,136, entitled SONDES FOR LOCATINGUNDERGROUND PIPES AND CONDUITS, issued May 22, 2007, U.S. Pat. No.7,298,126, entitled SONDES FOR LOCATING UNDERGROUND PIPES AND CONDUITS,issued Nov. 20, 2007, and U.S. Pat. No. 7,863,885, entitled SONDES FORLOCATING UNDERGROUND PIPES AND CONDUITS, issued Jan. 4, 2011. Thecontent of each of these applications is incorporated by referenceherein in its entirety (these applications may be collectively denotedherein as the “incorporated applications”). Various details of sondeoperation may be implemented as described in this incorporatedapplications in conjunction with the disclosures herein. Signalprocessing, output display generation, data transmission and reception,and other electronic circuit functions may be implemented in one or moreprocessing elements as described herein. Such processing elements mayalso implement sonde and/or locator functions as are described in theincorporated applications in various embodiments.

In some embodiments, the frequency emitted by the sonde may be selectedby the user, such as the user 150, and/or automatically selected by thesonde and/or an attached control device or system or locator. In yetother embodiments, a switching process between multiple frequencies maybe employed, which may provide increased resolution to an enabledlocator device. For instance, the sonde device may emit one frequencyover a known duration of time before switching to a different frequencyfor another duration of time prior to switching back to the originalfrequency. Examples of such frequency switching schemes are describedsubsequently herein in conjunction with FIG. 9.

Turning to FIG. 2, details of an exemplary sonde device embodiment 110are illustrated. The sonde device 110 may be largely cylindrical inshape and dimensioned to fit within a pipe such as the pipe 140 ofFIG. 1. Externally, the sonde device 110 may include an outer protectivecase or housing, such as an outer shell piece 210, a battery compartmentcap 220, and a threaded push-cable fitting 230. The battery compartmentcap 220 may be secured about one end of the outer shell piece 210 inorder to provide a water-tight seal to the internal components of thesonde device 110. Grooves/threads formed about the circumference of thebattery compartment cap 220 may allow a user to remove the batterycompartment cap 220 by hand and access a battery stored within, such asthe battery 510 illustrated in FIG. 5A. A series of locking bumps 212may be formed at the inner edge of the threads on the outer shell piece210 that may mate with locking bumps 222 formed on the outer edge of thebattery compartment cap 220. The mated locking bumps 212 and 222 mayallow for additional effectiveness in securing the battery compartmentcap 220 to the outer shell piece 210 in assembly. The outer shell piece210 and/or the battery compartment cap 220 may be composed oftransparent material allowing light from an LED 240 to be visible to auser that may, for instance, be used to indicate the device has beenactivated. In some embodiments, the LED 240 may be a RGB LED capable ofilluminating in different colors. In such embodiments, a scheme may beused whereby different colors may be used to indicate differentfrequencies. For instance, low frequencies may be indicated by a redlight where higher frequencies may be indicated by, for instance, a blueor purple light. The spectrum of colors between the red light indicatinga low frequency and the purple light indicating a high frequency may bereserved for frequencies in between the two. In such embodimentsemploying such an RGB LED, some colors may be reserved for indicatingother information. For instance, a white light may indicate a lowbattery to the user. In some embodiments, colored labels may also beplaced onto or inside the transparent enclosure 210 to indicatefrequency. Enclosure 210 may similarly be colored opaque or translucentto indicate frequency. The spectrum of rainbow colors may be utilizedfrom red to blue and then purple to indicate low to high frequencies.Multi-frequency sondes may use dual coloring to indicate the frequenciesbeing used.

In the sonde device embodiment 110, a standard AA battery may be used topower the device. In some embodiments, other battery types may also beused including standard sized as well as custom batteries. In otherembodiments, a cable reel and a push-cable may be used to provide powerto the sonde device through wires disposed adjacent to, on, or withinthe push-cable. The push-cable fitting 230 of the sonde device 110 maybe made to extend through the end of the outer shell piece 210 oppositethat of the battery compartment cap 220.

A push-cable, such as the push-cable 120 of FIG. 1, may be configured tomate with the threads of the push-cable fitting 230, thus securing thesonde device 110 to the push-cable. In manufacture, potting compound maybe applied within and around the push-cable fitting 230, therebysecuring the push-cable fitting 230 to the outer shell piece 210 and acore assembly 320 as illustrated in FIG. 3, and further providing awater tight seal. The push-cable fitting 230 may also be insert moldedinto shell 210. Push-cable fitting 230 may also be thermally orultrasonically inserted and fused with shell 210.

Turning to FIGS. 3-5A, a potting plug 310 may be dimensioned to fitsnugly within the push-cable fitting 230 and be used to restrictbackflow of potting compound during the manufacturing process. Internalto the outer protective structure, the sonde may include a core assemblyincluding core elements, wiring to form a coil, and core/coil structuralsupports which may be made of non-conductive materials such asfiberglass, plastics, as well as other materials such as carbon fiber,etc.

In the embodiment shown, a core assembly 320 may be largely cylindricalin shape and dimensioned to fit within the outer shell piece 210. A coreassembly keying feature 322 may be made to mate with a shell keyingfeatures 412 (FIG. 4) located along the inner walls of the outer shellpiece 210 to prevent unwanted rotations of the core assembly 320.Optionally, a product label 330 may be adhered about the core assembly320 and used to convey pertinent information regarding the sonde device110 to a user, such as in embodiments where the outer structure istransparent or includes a transparent window.

The core assembly 320 may include a threaded core sleeve 340 which maymate with threads formed along the inside of the battery compartment cap220. In assembly, a core sleeve O-ring 350 may be seated between thethreaded core sleeve 340 and the battery compartment cap 220 to providea water-tight seal.

A battery contact spring 360 may be seated within the batterycompartment cap 220. In use, the battery contact spring 360 may beassembled such that the current path from a battery to internalelectronics is only closed in the last quarter to half revolution so asto provide a way to activate and deactivate the sonde device 110. Inother embodiments, a magnetic switch may be used to activate and/ordeactivate a sonde device such as the sonde device 110. As illustratedin FIG. 5A, the hall-effect sensor 540 may be enabled to operate as amagnetic switch. In other embodiments, sonde devices in accordance withthe present disclosure may use a variety of other switching technologiesincluding, but not limited to, controls placed on a cable reel, wirelesscommunications between an enabled locator device and sonde device, aswell as the use of a variety of other mechanical and electronicswitching mechanisms. Such mechanisms may be wired or wireless.

Turning to FIG. 5A, a coil sub-assembly 520 may be formed along thelength of the core assembly 320, which may include one or more coilsusing a series of windings of ferromagnetic wiring such as, for example,litz wiring. With multiple coils, the coils may be configured as astep-up transformer. For example, the coils may include a series ofprimary antenna coils 522 and secondary antenna coils 524.

In operation, the combination of a primary antenna coil, such as theprimary antenna coils 522, and secondary antenna coils, such as thesecondary antenna coils 524, may act as a step-up transformer producinghigh voltage and high current in the secondary antenna coil dependent onthe number of windings and wire diameter and kinds employed. Highercurrents in the secondary winding create stronger magnetic fields fordetection by the associated locator. In alternate embodiments, differentnumbers of windings and materials and diameters for coils may be used.For instance, a sonde device as described in the present disclosure mayinclude a single antenna coil rather than utilizing primary andsecondary coils.

In accordance with one aspect, a core assembly of a sonde may includemultiple core section elements, which may comprise ferrite or otherhigh-frequency materials for sondes operating at higher frequencies. Forsondes operating at lower frequencies, multiple core section elements ofa similar configuration to that described herein may be made of softsteel or other ferromagnetic materials. In various embodiments, use ofmultiple core section elements may aid in reducing eddy currents and/orprovide other advantages. In an exemplary embodiment, the core sectionelements may include an arc-shaped cross section, with the arc formed toconform to the shape of the sonde, such as an arc section of a circularcross-section sonde.

In some embodiments, a resonant or LC circuit, such as the LC circuit550 of FIG. 5B may be used to generate desired or selected frequencies.In such embodiments, a primary coil 560 and a secondary coil 570 may bewound about a ferrite core 580. The ferrite core 580 may be composed ofone or more sectional ferrite piece in keeping with the presentdisclosure. The ferrite core 580 may act as a magnetic shield to reducemagnetic field intensity inside the ferrite core 580. Components housedby the ferrite core 580 may not cause undue magnetic losses and mayallow for the creation of a higher frequency sonde with a degree of Q toincrease the output power, range, and conserve battery power.

Turning to FIGS. 6-8, the core assembly embodiment 320 may include aninner core tube 610 around which a plurality of ferrite arc core sectionelements 620 may be secured by an outer core tube 630. In the exemplarycore assembly 320 there are four ferrite arc section elements 620 used,however, in alternative embodiments, the ferrite arc section elementsmay instead be constructed of materials with similar properties of highmagnetic permeability and low electrical conductivity to aid inpreventing eddy currents from forming and/or may have different numbersof section elements. Examples of alternate embodiments are describedsubsequently herein, such as embodiments having two or three sectionelements. Other embodiments (not shown) may include more than foursection elements.

The arc core section elements may be surrounded, either internally,externally, or on both sides by structural support elements, such ascore tubes. For example, an outer core tube 630 may includenon-conductive materials such as fiberglass resin or othernon-conductive materials to prevent eddy currents from forming The arccore section elements may be enclosed by and/or bonded to inner and/orouter core tubes to aid in positioning. Gaps between the arc coresections may be used to run power and/or signal wiring through thesonde. For instance, return wires 682 may be secured within the gapsbetween the arc core sections.

The windings of the coil sub-assembly 520 may be seated along theexternal surface of the outer core tube 630. The threaded core sleeve340 may be seated about the end of the core assembly 320 nearest thecompartment containing the battery 510 as illustrated in FIG. 5A. A coreinsert ring 640, which may be disposed below the threaded core sleeve340, and a top core retainer 650, which may be disposed about theopposite end thereto, may function to secure the core assembly 320together. The core insert ring 640 may also include a core ring slit 642disallowing eddy currents to form in the core insert ring 640 preventinga shorted turn. A set of wiring holes 644 may also be formed through thecore insert ring 640 allowing wiring to pass through. Within the innercore tube 630, a printed circuit board (PCB) holder piece 660 and PCB0-ring 670 may be seated above the compartment containing the battery510 (FIG. 5A) such that a watertight seal may be formed to protect a PCB680 secured to the PCB holder piece 660. A printed circuit pin 690 maybe made to pass through PCB holder piece 660 and electrically connect abattery, such as the battery 510 of FIG. 5A, to the PCB 680. The PCBholder piece 660 may be formed with a connection limiting feature 660 athat may prevent a battery from make an electrical connection when thebattery has been installed backwards.

As shown in FIGS. 7 and 8, a set of return wires 682 may provide anelectrical connection between the PCB 680 and the battery contact spring30 (FIG. 3). In use, the battery contact spring 360 and return wires 682may be assembled such that the two components make contact, thus closingthe current path from the battery 510 of FIG. 5A to the PCB 680, in thelast quarter to half revolution of the battery compartment cap 220 withattached battery contact spring 360. In assembly, the battery contactspring 360 may avoid contacting the core insert slit 642 of the coreinsert ring 640 (FIG. 6) to close the circuit so as to allow eddycurrents to form. A set of coil leads 720 may provide an electricalconnection between the PCB 680 and the primary antenna coils 522 andsecondary antenna coils 524 (FIG. 5A). As best illustrated in FIG. 8,the gaps or openings between the ferrite arc core section elements 620may provide for an ideal passageway for the return wires 682 and thecoil leads 720 from the PCB 680 to be routed to their respectivecomponent destinations.

Turning to FIG. 9, a frequency switching scheme, such as the switchingprocess embodiment 900 as shown, may include providing output magneticfield signals from the sonde at two or more frequencies. The frequencyswitching process 900 illustrates a scheme whereby two frequencies, 512Hz and 32,768 Hz, may be switched between in a timed interval, repeatingon a one second interval. Periods in which no transmission occurs mayalso exist between switching of frequencies to prevent ringing ofdigital filters on an enabled locator device such as the locator device160 of FIG. 1. Other frequency, phase, and/or time-varied schema may beused in various embodiments. Different frequencies used in the switchingscheme may be generated by tuning and/or filtering harmonics of a basefrequency to obtain the higher frequency signals, by directly generatingthe desired frequencies, or by other signal generation techniques as areknown or developed in the art. The output of both frequencies may remainphase locked to a common clock. The higher frequency may be an integermultiple of the lower frequency. The frequencies may both be powers oftwo.

An enabled locator device may also synchronize its time with a sondedevice in order to ensure the locator device is only accounting forsensed signals when the transmitted frequency is at an interval of fullamplitude and/or to avoid ringing of digital filters on the locatordevice or other signal processing constraints. Examples of timesynchronization methods may include time synchronization using GPSreceivers at both the locator and inducer, or other systems generatingtiming signals, ISM, cellular, or other radio communications to receivetiming information and/or coordinate timing between locators andinducers, using known (at the locator) pre-defined switching patterns,and/or any other mechanism known or developed in the art for sharingsuch information.

Further example ways of synchronizing time of a locator device andanother associated device are described in co-assigned U.S. ProvisionalPatent Application Ser. No. 61/561,809 entitled MULTI-FREQUENCY LOCATINGSYSTEMS AND METHODS filed Nov. 18, 2011, the content of which isincorporated by reference herein. In some embodiments, the sonde devicemay have a dial or similar mechanism allowing the user to manuallyselect the desired frequency to transmit. In some embodiments, thefrequency transmitted by the sonde device may be selected remotely by anenabled locator device or via the cable-drum. It may be further notedthat a different number of frequencies may also be utilized. In someembodiments, a locator device may also be configured to recognize apre-defined pattern of transmitted frequencies. In such embodiments, thelocator device may recognize the pattern of frequencies transmitted andsynchronize to the pattern accordingly.

Example Sonde Core Embodiments

As is known in the art, fabrication of ferrite core elements can bedifficult, especially if elements of long axial length are desired(e.g., long cylindrical tubular structures). At the same time, for sondeapplications it is frequently advantageous to have a long cylindricalcore, and materials such as ferrite are highly preferable for highfrequency device operation.

Ferrite core element manufacturing typically includes extrusion of aferrite paste material through an extruder die at pressure. Forcylindrical or other hollow-shaped extrusions, positioning of theextruded material on a similar cylindrical form is typically required inorder to maintain shape. However, for larger-sized and/or longerextrusions, the extruded paste may slip or slide on the form, therebydistorting the shape and/or creating cracks, gaps, or other defects.Consequently, forming precisely shaped cylindrical ferrite cores isdifficult and typically expensive.

Once the extrusion has been formed, it is then typically fired orotherwise cured to form a hard but brittle structure. Supporting ahollow tubular thin walled ferrite structure during firing or sinteringis also difficult and problematic.

Hard brittle cylindrical ferrite structures, when disposed in a sonde orother device, are subject to damage such as cracking from being dropped,from being pressed into contact with pipe interiors, being pressed byother sonde interior elements or structures, or from other actions.Cracked ferrite core elements can strongly affect the magnetic fieldsignals generated by the sonde, thereby weakening and/or distorting theoutput magnetic fields.

Accordingly, in one aspect, a core structure including multiple “arcsection elements,” such as core arc section elements 620 as shownpreviously in FIG. 6, may be manufactured and used in a sonde devicerather than using a single cylindrical tubular ferrite core structure(not shown). These arc section elements may advantageously be easier tomanufacture, may be lower in cost, may provide enhanced performance,such as by reducing device performance upon cracking of only one ofmultiple arc section elements (as opposed to cracking of the entire corewhen a single tubular core is used), and may provide other advantages,such as by providing routing paths for power and or signal wiring or forother components or structures.

FIG. 10 A illustrates one example embodiment of an arc section core 1000with four ferrite arc core section elements, elements 1010A, 1010B,1010C, and 1010D. These elements are denoted “arc” core section elementssince at least a portion of the interior side of the elements may beformed with a curved or arc shape to substantially match a cylindricalsupport form's outer surface. Each of these core section elements may beseparately manufactured, such as by extrusion, molding, or otherferrite/ceramic manufacturing techniques as known or developed in theart.

In an exemplary embodiment, an extrusion die having a shapecorresponding to the desired arc section core element cross-section maybe used for extruding paste material onto a form, thereby allowingbetter support of the material before firing. Since the arc sectionsneed not be hollow in the middle, advantages in forming andmanufacturing may be achieved over hollow-centered cylindrical tubularextrusions.

FIG. 10B illustrates example arc core section elements 1010A and 1010Cfrom core 1000 of FIG. 10A. Each of these section elements may beseparately manufactured and then positioned around a support structure,such as through frictional contact, adhesives, etc. Since there areseparate core section elements, they may be more resistant to impact ortwisting breakage (as compared to a single tubular ferrite core) insondes using this type of core structure. Further, manufacturingtolerances may be lower since the core section elements may bepositioned with varying gaps between each other, particularly if theyare mounted on a support structure of slightly larger diameter than theinside diameters of the arc core section elements when placed in directcontact. Another potential advantage may result in the event of impactsor twisting, in which case even if one of the arc core section elementsbreaks, others may not. This may allow for continued better performanceof a sonde using multiple arc core section elements as compared to asonde using a single hollow tubular core (where the entire core islikely to break upon impact). There may be other potential advantages inmanufacturing, sonde configuration, and operation. For example, asdescribed previously herein, wiring or structures may be disposed in thegaps between arc core section elements to allow for reductions in sizeand/or other performance benefits.

In various embodiments, different numbers of arc core section elementsmay be used. For example, FIG. 11 illustrates an embodiment of a coresection 1100 having two arc core section elements, while FIG. 12illustrates an alternate embodiment having three arc core sectionelements. Other embodiments (not shown) may have more arc core sectionelements. Some embodiments may use elements having other cross-sectionalshapes. For example, if a larger number of elements are used in thecore, each element may have a rectangular cross-section (i.e., be formedas long rectangular cross-section ferrite bars, or be formed initiallyas bars and then slightly bent or curved to allow for placement around acircular cross-sectioned support structure) rather than having anarc-shaped interior surface.

FIG. 13 illustrates details of an embodiment 1300 of a sonde corestructure including four arc core section elements forming a ferritecore 1000 and a non-conductive inner tubular structural support 1310,which may be made of non-conductive plastics, fiberglass, or othermaterials. Additional sonde device elements may be disposed withinsupport 1310. For example, as shown in FIG. 14, a battery 1420 and oneor more printed circuit boards 1430 or other circuit elements or modulesmay be disposed within support 1310 in the center of the sonde core.Sonde device operation may be enhanced by positioning the power supply(e.g., battery 1420) and associated electronics (e.g. circuit boardmodule 1430) partially or fully within the ferrite core 1000.

FIG. 15 illustrates an example sonde device embodiment 1500, which maycomprise embodiment 1400 or other core structures along with one or morecoil windings 1510, which may be disposed around arc core sectionelements or outside an additional structural element (not shown)positioned on the outside of the arc section core elements (e.g.,another fiberglass cylindrical structure similar to support structure1310 but positioned outside of the ferrite arc core sections).

Turning to FIGS. 16A-17, an embodiment 1600 of a sonde device may allowfor a central passage 1610 allowing the sonde device 1600 to secureabout cabling, hose, or the like. Such an embodiment may be powered bybatteries, such as Lithium Polymer batteries 1620 best illustrated inFIG. 17. The batteries, such as the Lithium Polymer batteries 1620, maybe wrapped into curved sections allowing them to be securedcircumferentially about the central passage 1610. Core sections 1630 inkeeping with the present disclosure may be secured about the batteries1620, enclosing both the batteries 1620, the central passage 1610, aswell as other internal electronics and components not illustrated. Coilwindings 1640 may in turn may be secured about the core sections 1630. Asonde housing 1640 may further encapsulate the aforementionedcomponents. In some embodiments, the battery or batteries may be locatedaway from the coil windings and/or not encapsulated by the coresections. For instance, the embodiment 1660 of FIG. 16B may havebatteries 1665 located on the wrapped ends of the sonde device 1660secured outside of the core sections 1670. Coil winding 1675 may wrapcentrally about the core sections 1670 between the batteries 1665. Asonde housing 1680 may further encapsulate the internal components suchto allow a central passage 1685 to be formed.

In some embodiments, one or more core sections may be used along thelength of a sonde device in keeping with the present disclosure. Asillustrated in FIG. 16C, a lengthwise sectioned core embodiment 1690 mayutilize multiple core sections lengthwise, such as the three coresections 1695. In such embodiments, the circumferential breaks betweencore sections may be staggered with the circumferential breaks betweencore sections of other rows of core sections.

The central passage 1610 may allow for the sonde device 1600 to beideally used in, for instance, horizontal directional drilling, otherboring tools, push jetters, and other scenarios where a passage isneeded for fluids, material, drilling or cutting tools, slurries, and/orcabling to pass through. As illustrated in FIG. 18, a sonde device 1800similar in design to the sonde device 1600 of FIG. 16A or the sondedevice 1660 of FIG. 16B may be secured to hose 1810 of a sewer jetter orpush jetter 1820. Details and information regarding sewer or pushjetters may be found in U.S. patent application Ser. No. 13/073,919,entitled PIPE INSPECTION SYSTEM WITH JETTER PUSH-CABLE, filed Mar. 28,2011, the content of which is incorporated by reference herein. Asillustrated in FIG. 19, a sonde device 1900 similar in design to thesonde device 1600 as illustrated in FIG. 16A or sonde device 1660 ofFIG. 16B may be secured to drill string 1910 of a horizontal directionaldrilling system 1920. In yet other embodiments, a sonde similar to thesonde device 1600 may be built directly into certain devices. Forinstance, a sonde device may be built onto or installed into a drillstring section.

Turning to FIG. 20, some embodiments may be configured to be inductivelycharged. For instance, the sonde device embodiment 110, when coupledwith an appropriate battery, may be charged by inductive chargermechanism 2000. The sonde device 110 may be placed within anappropriately dimensioned cavity 2010 a in the inductive charger housing2010. Internally, inductive charge coils 2020 may surround cavity 2010a. The inductive charge coils 2020 may further be wired to an enabledcharge circuitry 2030 which in turn may be coupled to an appropriatepower source.

Turning to FIG. 21, in some embodiments of a sonde device in keepingwith the present disclosure, such as the sonde 2110, an inductivecharger such as the inductive charger 2120 may utilize a clamp 2130 tosurround and charge the sonde 2110. An inductive charger such as theinductive charge 2120 may be ideal for inductively recharging sondeembodiments that may be built onto a cable, hose, drill string, or othersystem which may otherwise be cumbersome to disconnect the sonde.

As illustrated in FIG. 22, the angle Θ from the horizontal with respectto gravity {right arrow over (g)} may be determined through, forinstance an accelerometer in an enabled sonde device such as sonde 2200.The deviation from the horizontal or vertical axis with respect to thesondes axis may be used and transmitted to an enabled locator device2210 partially obscured from view in FIG. 22.

In some embodiments, a sonde device in keeping with the presentdisclosure may be configured to transmit data via a transmitter ortransceiver module. This data may include, but is not limited to, themeasurement of the angle Θ 2310 as defined in FIG. 22 as well as thesonde signal strength or current power level i 2340 over time. The databroadcasted from the sonde, the measured angle Θ 2310 for instance, maybe received and displayed by a locator device. By knowing the currentpower level i 2340 of a sonde device, an enabled locator may eliminateone unknown thus making it easier for solving for other unknownparameters, such as buried object location or depth. For example,knowledge of transmitted power may be used in a locator signalprocessing circuit, in conjunction with received signal strength,angular information, phase information, and the like from one or moreantennas to refine estimates of location and depth of a buried objectsuch as a pipe or conduit, or other cavity in which the sonde ispositioned. An enabled locator may further utilize broadcasted currentpower level i 2340 to determine signal strength loss due to pipematerial and thereby determine pipe material. Binary phase shift keyingor other encoding schemes may be used in transmitting this data.

Alternative embodiments of a sonde device in keeping with the presentdisclosure may be enabled to regulate constant power to a sonde with aknown current. The signal output by the sonde may be measured and suchmeasurements may be used to further control the output. Pulse-widthmodulation or other similar technique may be utilized to regulate thepower. In such an embodiment, an enabled locator may more easily locatethe sonde device. A locator device may further be enabled to communicatewith such a sonde device. In some such embodiments, an initialcalibration may be performed whereby the enabled locator device maymeasure the sonde strength in a known distance and orientation from thelocator.

In yet other embodiments, a sonde device in keeping with the presentdisclosure may be enabled to measure its own field strength andcommunicate this data to an enabled locator device. In such embodiments,the locator device may be enabled to recognize and compensate fordegradation of the magnetic field of the sonde device as its batterydischarges. This may allow for such an enabled locator device to moreeasily determine the position of the sonde device.

In some embodiments, temperature compensated crystal oscillators(referred to hereafter as TCXO) or voltage controlled temperaturecompensated crystal oscillator (VCTCXO) may be used to provide a preciseand stable time reference on the sonde to allow the phase to be trackedand/or allow synchronous detection techniques to be used.

In some configurations, the various systems and modules include meansfor performing various functions as described herein. In one aspect, theaforementioned means may be a processor or processors and associatedmemory in which embodiments reside, and which are configured to performthe functions recited by the aforementioned means. The aforementionedmeans may be, for example, processors, logic devices, memory, and/orother elements residing in a sonde or coupled element, such as a camerahead, camera control module, display module, and/or other modules orcomponents. In another aspect, the aforementioned means may be a moduleor apparatus configured to perform the functions recited by theaforementioned means.

In one or more exemplary embodiments, the functions, methods andprocesses described herein in conjunction with sondes and sondeoperations may be implemented in hardware, software, firmware, or anycombination thereof If implemented in software, the functions may bestored on or encoded as one or more instructions or code on acomputer-readable medium. Computer-readable media includes computerstorage media. Storage media may be any available media that can beaccessed by a computer. By way of example, and not limitation, suchcomputer-readable media can include RAM, ROM, EEPROM, CD-ROM or otheroptical disk storage, magnetic disk storage or other magnetic storagedevices, or any other medium that can be used to carry or store desiredprogram code in the form of instructions or data structures and that canbe accessed by a computer. Disk and disc, as used herein, includescompact disc (CD), laser disc, optical disc, digital versatile disc(DVD), floppy disk and blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer-readable media.

It is understood that the specific order or hierarchy of steps or stagesin the processes and methods disclosed are examples of exemplaryapproaches. Based upon design preferences, it is understood that thespecific order or hierarchy of steps in the processes may be rearrangedwhile remaining within the scope of the present disclosure. Anyaccompanying method claims may present elements of the various steps ina sample order, but are not meant to be limited to the specific order orhierarchy presented unless explicitly noted.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the embodiments disclosed herein may be implemented aselectronic hardware, computer software, or combinations of both. Toclearly illustrate this interchangeability of hardware and software,various illustrative components, blocks, modules, circuits, and stepshave been described above generally in terms of their functionality.Whether such functionality is implemented as hardware or softwaredepends upon the particular application and design constraints imposedon the overall system. Skilled artisans may implement the describedfunctionality in varying ways for each particular application, but suchimplementation decisions should not be interpreted as causing adeparture from the scope of the disclosure.

The various illustrative logical blocks, modules, functions, andcircuits described in connection with the embodiments disclosed hereinmay be implemented or performed in a processing element with a generalpurpose processor, special purpose processor, digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine, which may be programmedto perform the specific functionality described herein, either directlyor in conjunction with an external memory or memories. A processor mayalso be implemented as a combination of computing devices, e.g., acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

As used herein, computer program products comprising computer-readablemedia including all forms of computer-readable medium except, to theextent that such media is deemed to be non-statutory, transitorypropagating signals.

The scope of the invention is not intended to be limited to the aspectsshown herein, but is to be accorded the full scope consistent with thelanguage and drawings herein, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. A phrase referring to“at least one of a list of items refers to any combination of thoseitems, including single members. As an example, “at least one of: a, b,or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, band c.

The previous description of the disclosed aspects is provided to enableany person skilled in the art to make or use embodiments of theinvention. Various modifications to these aspects will be readilyapparent to those skilled in the art, and the generic principles definedherein may be applied to other aspects without departing from the spiritor scope of the disclosure. Thus, the presently claimed invention is notintended to be limited to the aspects shown herein but is to be accordedthe widest scope consistent with the appended claims and theirequivalents.

We claim:
 1. A sonde device, comprising: a housing; a core including: aplurality of core section elements; and a support structure forpositioning the core section elements; and a winding disposed about thecore structure.
 2. The sonde device of claim 1, wherein the core sectionelements are arc core section elements.
 3. The sonde device of claim 1,wherein the core section elements comprise ferrite.
 4. The sonde deviceof claim 1, wherein the core section elements comprise steel.
 5. Thesonde device of claim 1, wherein the core section elements have arectangular cross-sectional shape.
 6. The sonde device of claim 1,wherein the plurality of core section elements comprises four or morecore section elements.
 7. The sonde device of claim 1, wherein the corefurther includes a battery and a circuit element for providing currentto the winding to generate an output magnetic field signal.
 8. The sondedevice of claim 7, wherein the battery and the circuit element aredisposed at least partially within a volume enclosed by the plurality ofcore section elements.
 9. The sonde device of claim 7, wherein thecircuit element includes circuitry for generating the current to providethe output magnetic field signals at two or more frequencies.
 10. Thesonde device of claim 9, wherein the output signal is switched betweenthe two or more frequencies.
 11. The sonde device of claim 1, whereinone or more signal or power wires are disposed in an axial gap betweenones of the plurality of core section elements.
 12. The sonde device ofclaim 1, wherein the support structure comprises a non-conductivetubular structure.
 13. The sonde device of claim 12, wherein thenon-conductive tubular structure is a fiberglass structure.
 14. Thesonde device of claim 1, wherein the winding comprises a single winding.15. The sonde device of claim 1, wherein the winding comprises a primaryand a secondary winding.
 16. The sonde device of claim 1, furthercomprising one or more lights to indicate a sonde status.
 17. The sondedevice of claim 16, wherein the one or more lights include a colorlight.
 18. The sonde device of claim 1, further comprising a transmittercircuit configured to communicate data to an enabled locator device. 19.The sonde device of claim 18, wherein the communicated data includessonde signal strength data.
 20. The sonde device of claim 1, furthercomprising a multi-color lighting device, wherein the lighting deviceprovides a color corresponding to an operating frequency of the sonde.21. The sonde device of claim 20, wherein the multi-color lightingdevice comprises an red green blue (RGB) light and a color controlcircuit for generating the color corresponding to the operatingfrequency based on a signal provided from a processing element of thesonde.
 22. The sonde device of claim 20, wherein battery statusinformation is provided from the lighting device.
 23. The sonde deviceof claim 22, wherein the battery status information includes a low powerstatus, and the lower power status may be provided with a specific colorof light and/or a unique flashing light sequence.
 24. The sonde deviceof claim 22, wherein the battery status information includes a fullycharged power status, and the fully charged status is indicated with aspecific color of light or a unique flashing light sequence.
 25. Thesonde device of claim 1, wherein the sonde includes a passage forallowing materials to be pumped through or removed to facilitate jettingor drilling.
 26. The sonde device of claim 1, further comprising atransmitter or transceiver module configured to send and/or receivedata.
 27. The sonde device of claim 26, wherein the transmitter ortransceiver module is configured to send data defining a sondeorientation from a horizontal or vertical axis.
 28. The sonde device ofclaim 26, wherein the transmitter or transceiver module is configured tosend data defining a sonde signal strength or output power level orother output signal characteristic such as phase, frequency, amplitude,or modulation type.
 29. The sonde device of claim 1, wherein the sondeincludes a precision time reference circuit for providing a timereference for tracking phase of a generated signal.
 30. The sonde deviceof claim 1, wherein the sonde includes a circuit for receiving anelectromagnetic field signal and charging a battery using the receivedelectromagnetic field signal.
 31. The sonde device of claim 1, whereinthe sonde includes an inductive charging circuit and a rechargeablebattery coupled to the inductive charging circuit.
 32. The sonde deviceof claim 1, further comprising a magnetic switch and a circuit coupledto the magnetic switch to activate or de-activate the sonde responsiveto a switching action of the magnetic switch.
 33. The sonde device ofclaim 1, wherein the frequency of an output of the sonde may be switchedat a predefined or selected rate.
 34. The sonde device of claim 33,wherein multiple output frequencies are provided and wherein two or moreof the multiple output frequencies are phase locked to a common clock.35. The sonde device of claim 34, wherein two or more of the multipleoutput frequencies are integer multiples.
 36. The sonde device of claim34, wherein one or more of the multiple output frequencies are multiplesof two of one or more other output frequencies.
 37. The sonde device ofclaim 1, wherein the plurality of core section elements comprisemultiple lengthwise core sections.
 38. The sonde device of claim 37,wherein circumferential breaks between core sections of a first row ofcore sections are staggered with circumferential breaks between coresections of a second row of core sections.